Apparatus for transforming electrical energy



April 13 1926. l,580,554'

J. E. 'C ALVERLEY ET AL APPARATUS FOR TRANSFORM ING ELECTRICAL ENERGY Filed March 26, 1920 3 Sheets-Sheet 1 WJLtPT$ we. a. mm M I April 13, 192 6.

1,580,554, E. CALVERLEY ET AL APPARATUS FOR TRANSFORMING ELECTRICAL ENERGY s Sheets-Sheet 2 Filed March 26, 1920 Aprll 13 1926. V J. I VERL Y AL I UNETED STATE rarest Fries.

JOHN EARNSI-IAW GALVERLEY AND WILLIAM EDEN HIGHFIELD, or PRESTON,

ENGLAND.

APPARATUS FOR TBANSFORIVIING ELECTRICAL ENERGY.

Application filed March 26, 1920. Serial No. 369,001.

To all whom it may concern:

Be it known that we, JOHN EARNSHAW GALVERLEY and .Vrnmmr EDEN Hiei-rrrnnn, subjects of the King of England, both residing at Preston, in Lancaster, England, have invented certain new and useful Improvements in Apparatus for Transforming Electrical Energy, of which the following is a specification.

This invention relates to apparatus for ransforming alternating-current electrical energy into direct-current form and vice versa, or to trans orm direct-current of one voltage to direct-current of another voltage. The type of apparatus for the said purpose, and to which this invention relates, is that in which one or more transformers are employed whose one set of windings is so interconnected as to provide a closed circuit in which the total electromotive force at any moment is Zero if the windings are operating as a secondary to the transformer or transformers, and the said closed circuit is connected to commut-ating gear in substantially the same manner as the winding of a Gramme ring armature is connected to its connnut-ator.

The object of the present invention is to provide an improved construction of the said type of apparatus such as shall be suitable for operation with really high voltages, such for example as 100,000. To secure this, the present invention provides a construction which is more convenient to carry out and enables better insulation to be provided than has heretofore been the case with proposed apparatus of this type. The means adopted to these ends comprise the employment of a special subdivision of the closedcircuit connected to the commutating gear and the employment of two or more commutators arranged electrically in series. The said closed circuit or portions thereof will hereinafter be described as secondary'but it will be obvious that, when transformation from directcurrent to alternating current is taking place, the function of this winding or its parts is that .of a primary winding. a

This invention is. now further described by reference to the accompanying drawings in which- Figure 1 is a diagrammatic illustration of an pparatus h g e WWWWW in series together with the appropriate transformers, the connections to one commutator being omitted for the sake of clearness.

Figure 2 is a diagram showing the connections for the primary windings with a corresponding phase diagram therefor.

Figure 3 is a diagram similar to a portion of Figure 1 but showing a series parallel arrangement of commutators.

Figures 4: and 5 are diagrams of modi' fied connections employed for the purpose of obtaining a lower speed than is needed for the connections of Figure 1, and

Figure 6 is a side elevation of a modified arrangement of a pair of eommutators.

The apparatus illustrated in Figures 1 and 2 is intended for the conversion of three-phase alternating-current to directcurrent.

The apparatus comprises two three-phase transformers A and B, the windings whereof will hereinafter be described as primary and secondary respectively, without the in tention, by the use of these terms, to restrict the-suggested function of any coil to be that of primary or secondary. The particular function of a coil will depend upon whether the apparatus is transforming from alter nating current to direct current or vice versa. The term primary will, however, be uniformly applied to the winding which receives or delivers alternating current as such, and the term"secondary to the other set of windings, namely that which is connected to the commutator or commutators.

Each of the transformers is of the wellknown threedeg type, and the primary coils on each leg are indicated at A and B respectively. The coils A are connected, as shown in Figure 2, each entirely in one line of a three-phase supply X, Y, Z, while the coils B are interconnected in the manner illustrated to produce fluxes in the legs of transformer B whose phase relations with reference to those in the legs of transformer A are as indicate by the vectors 1, 2 and 3 in the phase diagram of Figure 2. The secondary windings are indicated at A and B respectively, audit will be noted that for every primary winding there are four secondaries thus enabling secondary phases to he obtained corresponding with each of the vec Q aX Y Z, 1 2, 3, in th phase diagram of Figure and also with spectively. In the diagran'i the tour secondary coils on any one leg are shown two on one side of the primary and two on the other side, the two together on one side constituting a secondary section and both belonging to the same connnutator and being connected di rectly to it only. so that the other section, on the opposite side otthe primary, is distinct from it and is electrically connected directly to its own connnutator alone and in series with the first section by way of the coininiitators alone.

Only half the secondaries of the diagram are shown connected in the drawing, iialnrely those that are connected to the inents C oi": a coinn'iutator C. There is second coiinn'utator D whose segments are connected to the remaining secondary coils in exactly the san'i'e way asare the segments (l to the secondary coils as shown.

Each commutator is provided with brushes shown at C D respectively, carried upon arnis C, D that are mounted upon a shaft E by which they are rotated. Slip rings F and G with brushes F G are also provided arranged coa ;ially with the commutators C and D, the b1 ushes' F G being mounted upon the shaft E to rotate with it, The brush F is connected by a connector F n'i'ounted upon the shaft, to one of the brushes C the other brush C is connected by a connector C upon the shaft to one of the brushes D while the other brush D is similarly connected by aconnector l) to the brush G The slip rin s and commutator-s are therefore all in series with one another.

it will be appreciated as obvious. that for correct operation it is not sultieient merely to have the brushes rotated at the correct sgased, they must be truly synchronized so that each brush is situated at every lnoi'i'i'ei'it at a point on its coni'inu'tator m1 respondii'ig electrically to the point to which the brushes have to be set in an ordinary direct-current machine. In other words, what may be described as nodal points of E0 di ributimi of electroniotive force aro'iiind the coinniutato'r revolve round the conin'u'itator, and each brush must at all tinies be coincident with one such node or at least niust be in its immediate vicit. 5

In order to secure this coinlition at ail tunes, provision may be na'de to advance or retire the shaft angulatly while it is run nin'g. This pro .cion may, for example, take the toiin insane for field strength of the synchronous motor diivi the shatt orof L anstor adjusting the stator of this motor ang'ularly around the rotational axis of the shaft.

varying the In the drawing, the brush arms C" and D are shown parallel with one another. In some cases, however it may be necessary to have them arranged as though one or more were angular-1y displaced froin such a position with relation to the remainder. Any convenient means may be employed for this purpose, such for example as an adjustable coupling as indicated diagrammatically at K in Figure 1. An alternative method for producing a similar result consists in so connecting the segments on a coininutattnrto the coils of its closed circuit, that they are in. advance tingularly of those segments on another coininu'ta'tor that are connected to the corresp'onding coils of its own closed circuit.

It is to be understood that the diagram and circuits above described are given in a simple form, there being only two coils per transformer liinb for each coninr ator, each coil of which is connected to two co1n n'rutator bars; .lt will be obvious to any person skilled in the art that the coils can be further subdivided and connected to coinn'iutator bars interi'nediate between those shown in the diagran'i so as to obtain a suitble subdivision of the eleetroinotive force between adjacent bars. v

()briously, a said secondary section Ina consist, wholly or in part, of windings ar ranged in parallel with one another for the sake of carrying or delivering increased current at a correspondingly less voltage, and any series parallel arrangement may be e1nployed in the windings or even in the comn'iutat-ors.

The, primary supply will be understood to be, fed to the primaries from the mains X, Y, Z, whereas the, connections between the secondaries and the coinlnutators may be described giving a two-pole, two-circuit, wave winding and the nodal points of the distribntion of electron'iotive force around the coininutator will rotate round the coin- .inutators at 3,000 revolutions per minute it the prinlary supply is 0t cycles per secand, The shaft Eniust therefore rotate at the same speed of 3,000 revolutions per minute. The. direct-,ci'n'rent output is obtained from the leads H, H I

li here' it is desired for n'iechanical or other reasons to have a slower speed of rotation. for theshatt and brush gear, the secondary windings can be interconi'iected with one another and their coininutators to give the equivalento if inultipolar D. C; Wind ings .thus obtaining other speeds which are synchronous with the frequency of the priniary supplyp'lwo ways are shown of do-' ing this, naniely that in Figure t where one of the connnutators say the commutator Q, is shown with four, brushes spaced apart, the diametrically opposite brushes being connected together. An alternative method is that indicated in Figure 5 in which the pitch of the connections to the commutator is so selected as to give the equivalent of a four-pole multipolar D. G. wave winding. Only a part of the circuits is indicated in Figure 5, the remainder being obvious to any person skilled in the art.

It is to be understood that the primary object of the present invention is to obtain such potential differences between adjacent commutator bars, and in general between the different parts of the brush gear as shall enable satisfactory operation of the class of apparatus referred to, to be attained. ihe construction provided by this invention is favourable to'high insulation and readily applied insulation both of the windings and of the commutator gear, since the voltage in each section of the secondary winding is not only determined by the way in. which it is connected, but has a readily predetermined value with relation to the adjacent windings; moreover, by carthing the core its relation to the whole of the system is also readily predetermined. Hence each part can be appropriately insulated with simplicity of construction and satisfactory operation.

Figure 3 is a diagram showing an arrangement of four commutator-s, two in series anc two in parallel, enabling heavier currents to be dealt with satisfactorily than if two con'nnutat-ors in series were alone employed. Obviously any series parallel arrangement can be employed in an analogous manner.

A detail of construction provided by this invention is one in which two adjacent comimitators, for example the two commutators C and D of Figure 1, are arranged, not as indicated diagrammatically in the drawing with the back of one towards the face of the other, but face to face. Brush gear located between these faces can be arranged so as to put one of said faces into connection with the other. Such an arrangement is diagrammatically illustrated in Figure 6 in which three brush-arms C, I) and C, are shown, whereof the arms C and D carry brushes C and D respectively, which are connected re spectively to connectors F and D as de scribed above with reference to Figure 1, whilst the arm C carries a brush I) that connects the two commutators electrically in series with one another. Inthis arrangement the connections of the closed circuits to the segments C and D of the two comimitators is the same as described above with reference to Figure 1, except that those of the commutator D will be rotated angularly through 180, owing to the brush D to which the connector D is connected being displaced through 180 relatively to the position occupied by the corresponding brush in Figure 1,

The expression disc type, as applied to commutators, will readily be understood to denote a commutator whose segments are arranged on a plane face, usually circular, in contradistinction to the more commonly employed kind with the segments ona cylindrical face.

first we claim as our invention and desire .to secure by Letters Patent is 1. Apparatus for transforming electrical energy comprising a polypliase static transformer group, a plurality of secondary windings in each secondary phase of each transformer of said transformer group, a plurality of connnutators, connecting means for the secondary windings whereby they are formed into a plurality of similar closed circuits, each serving as the seat of a balanced polyphase system of electro-motive forces and each being connected to the ments of one of the commutators, comniutation gear comprising a negative brush and a positive brush on each commutator, means for producing relative motionbetween said bruslles and eommutators, said brushes on each commutator providing for the closed circuit associated therewith external connect-ions which divide the said circuit into two paths in parallel which are always of substantially equal and constant electrical values similar to the circuits of a Gramme ring armature, and connecting means between brushes on the respective commutators whereby the commutators with their associated windings are put in series and serve for. working with high tension continuous current.

2. Apparatus for. transforming electrical energy comprisinga plurality of transformer cores, primary windings in said cores, a plurality of pairs of similar secondary windings on each of said cores, a plurality of commutators, connecting means for the secondary windings whereby they are formed into a plurality of similar closed circuits each closed circuit including one pair of secondary windings from each of a plurality of cores and each said circuit serving as the seat of a balanced polyphase system of electro-motive forces and each being connected to the segments of one of the COl'l'l'. mutators. commutation gear comprising a negative brush and a positive brush on each commutator, means for producing relative motion between said brushes and commutators. said brushes on each commutator providing for the closed circuit associated therewith, external connections which divide the said circuit into two paths in parallel each of which always contains one of the secondary windings of each of the pairs of secondary windings included in the circuit and connecting means between brushes on the respective cores whereby the commutas.

tors ith their associated windings are put inseries and serve foiiworking with high tension continuous current,

3. apparatus for transforming electrical energy, static transforniing means having two sets of windings with each set con"- nected to constitute a closed circuit wherein the total electro inoti ve force at any moment is zero when the same is operating as a secondary, two stationary connnntators arranged co-axially one with the othe'iuwith their operative faces turned one towards the other, means connecting each closed circuit to one" of said mmmuta'tors whereby successive electric ally equidistant points in each closed circiiit are connected to successive segments of the allotted coininiitatoi and means comprising rotatable brushes connecting said coinmutatoi's electrically in series one with theother through said brushes.

l. In apparatus for transforming electrical energy, static transforin'ing niean's' having a secondary winding that is sub-divided into two sections of which the ma neti conditions are identical with one anotherand each section connected to o stitute a closed circuit iilh'erein the total electron'iotive force at any li'lOlnnl; is zero when the same functions as a se'con'clary, two" stationaryconiinutators spaced leads coi'ine'cting each section of said winding to the segments of only one coininuta'tor, and means comprising rotatable brushes connecting said coininutators electrically in series one with the other through said brushes each closed circuit being connected to its coininut-a'tor to give the electrical equivalent, as regards distribution of potential around the commutator, of a commutator connected to a 1nu1ti o1a1- direct-current armature.

a 'jijara'tus for transforming electrical energy, static transforming, means proyide'd with two sets of windings with each set connected to constitute a closed circuit wherein the total electroinotive force at any moment is Zero when the same is operating as a secondary, two stationary coniniutators of the disc type arranged co-axially one with the othermeans connecting each closed circuit to the segments of one of said C0111- Inutators whereby successive electrically equidistant points in each circuit are connected to successiveseginents of the allotted commutator, and means coinprising rotatable hi'us'l'ies 'connecting said con'nnutators electrically in series one with the other through said brushes.

t 6 In apparatus for transforming electricalenergy, static transforming means hatin'g two sets of windings with each set connected to constitue a closed circuit wherein the total electroinotive force at any moment is Zero when the same is opera-tingas a secondary, two stationary coininutators of the disc typ'earranged c'o-axially one with the other with their operative faces turned one towards the other, means connecting each closed circuit to one of said coininutators whereby successive electrically equidistant points in each closedcircuit are connected to successive segments oi the allotted coniinutzitor, and means comprising rotatable brushes connecting said colnniutators electrically in series one with the other through said brushes.

In testirnony whereof we have signed our names to this specification.

JOHN EARNSHAW CALVERLEY. WILLIAM EDEN HIGHFIELD. 

